Objective: This study was to evaluate the effects of individual or combinational use of phytase, protease, and xylanase on total tract digestibility of corn, soybean meal, and distillers dried grains with soluble (DDGS) fed to pigs.
Methods: Each experiment had four 4×4 Latin squares using 16 barrows. Each period had 5-d adaptation and 3-d collection. All experiments had: CON (no enzyme); Phy (CON+phytase); Xyl (CON+xylanase); Pro (CON+protease); Phy+Xyl; Phy+Pro, Xyl+Pro, Phy+Xyl+Pro. Each Latin square had 'CON, Phy, Xyl, and Phy+Xyl'; 'CON, Phy, Pro, and Phy+Pro'; 'CON, Pro, Xyl, and Xyl+Pro'; and 'Phy+Xyl, Phy+Pro, Xyl+Pro, Phy+Xyl+Pro'.
Results: The digestible energy (DE), metabolizable energy (ME), and nitrogen retention (NR) of corn were not affected by enzymes but the apparent total tract digestibility (ATTD) of phosphorus (P) was improved (p<0.01) by Phy. The DE and ATTD dry matter (DM) in soybean meal were increased (p<0.05) by Phy+Pro and the ATTD P was improved (p<0.01) by Phy, Phy+Pro, and Phy+Xyl. The DE, ME, and ATTD DM in DDGS were improved (p<0.05) by Phy+Xyl and the ATTD P was improved (p<0.01) by Phy, Phy+Pro, and Phy+Xyl.
Conclusion: Phytase individually or in combination with xylanase and protease improved the Ca and P digestibility of corn, soybean meal, and DDGS, from the hydrolysis of phytic acid. The supplementation of protease was more effective when combined with phytase and xylanase in the soybean meal and DDGS possibly due to a higher protein content in these feedstuffs. Xylanase was more effective in DDGS diets due to the elevated levels of non-starch polysaccharides in these feedstuffs. However, when xylanase was combined with phytase, it demonstrated a higher efficacy improving the nutrient digestibility of pigs. Overall, combinational uses of feed enzymes can be more efficient for nutrient utilization in soybean meal and DDGS than single enzymes.
Keywords: Corn; Distillers Dried Grains with Soluble (DDGS); Phytase; Pigs; Protease; Soybean Meal; Xylanase.